PORT ST. LUCIE, Fla. — Noah Syndergaard's frustration finally came to a boil midway through last July.

Beat up by the Pacific Coast League, his ERA hovered above five. A major league call-up that had seemed a fait accompli had not materialized and he remained in Triple-A. More difficult yet, Frank Viola, his pitching coach at Las Vegas, would not relent with his pupil.

Viola had returned to the team the previous month, missing two months while recovering from heart surgery. In Syndergaard, he saw a talented pitcher in need of guidance. All his career, Syndergaard had been able to get by with a fastball that zipped near 100 miles per hour and a curveball that awed even Mets manager Terry Collins.

Now, that was not enough. Viola tried to imbue into him the intellectual workings of pitching, pestering him with questions. The day after Syndergaard's starts, he would find Viola standing next to him asking what pitch he would throw in each situation as they watched that night's game.

In July, during one conversation Viola again asked him to explain why he had chosen to throw one pitch in a certain situation during his previous start. Disgruntled, Syndergaard shot him a look.

"Why don't you just call my damn game," he replied.

It caused Viola to step back and consider his place. He too had been a successful pitcher at one time, even winning a Cy Young, but every player matures at their own pace. At that point, he realized that behind the hulking 6-foot-6 physique and the uber-prospect acclaim, Syndergaard was just a 21-year-old still learning himself.

"He didn't mean it as a negative," Viola now says. "He just didn't want to have to think about this stuff."

It was another crucial point in the education of Noah Syndergaard, a valley before he began to rise again.

Yet, Viola says, Syndergaard is better than ever before. A season of deep-set struggles has changed him and bettered him. Syndergaard will testify to the results.

The crucible of hitter-friendly Las Vegas has turned him from robotic hard-thrower to pitcher. A curveball and changeup now provide steady compliments to that fastball. And a person who had difficulty handling the demands of his stature received what Viola deemed a "wake-up call."

"In the long run, sometimes struggling will get the most out of somebody down the line," Viola said. "And if he went out there last year and kicked ass like he did at every other level...I think the struggles are really going to pay dividends ten-fold once he gets to the big leagues. And I think that's going to be a hell of a lot sooner than people think."

Even Collins was surprised Syndergaard never made it to the Mets last season. Syndergaard was too. The hype around him last spring swelled so much that he spent the first half of last season continuously checking the Super-2 deadline, assuming a call-up would follow.

Nor could he escape the lure of Twitter replies and the news report of his status. Syndergaard did not ignore neither. The pressure consumed him, filling his mind with errant thoughts. He pitched like each start was his chance to earn a promotion.

At the All-Star break, Syndergaard sought change. He deleted the Twitter app off his phone. His parents now check the press clippings for him — though he did not miss the winter's trade rumors that swirled with his name.

"Once he got off his Twitter and once he stopped reading about all the crap that should've been going on or wasn't going on, once he realized 'Oh boy, I've got a job to do and I have to do it now'," Viola said. "I think that's when he started showing the maturity."

With Viola, he found a steady mentor. Syndergaard took to his lessons. Once he became willing to listen, the coach says, he turned into a sponge.

By late August, Viola noticed a modification. Syndergaard produced better workouts and side sessions between starts. He accepted there was improvement to be made. His attitude had adjusted to the rigorous demands, and his performance lifted too.

That has carried over to this spring. Viola says that Syndergaard that has arrived here is "not the same Noah I had last year. It's that drastic difference." His bullpen sessions are more precise. He is more confident and understanding.

Syndergaard's development is also a testament to the variable natural in which pitchers progress. Last spring there was a belief he would already have made his debut in Queens instead of facing another trip to Las Vegas. When he will be able to pitch in a rotation with Harvey, Zack Wheeler and Jacob deGrom is unknown.

For Viola, it is a reminder that, despite all the hyperbole, Syndergaard is still only 22 years old.

"Absolutely, especially when you have people to compare him to - Matt Harvey, Zack Wheeler," Viola said. "My lord. That's not fair. It's really not fair on anybody. Noah is 21 - he's 22 now. But he's not necessarily as mature as a 22-year-old Matt Harvey or a 22-year-old Zack Wheeler or even a 25-year-old Jacob deGrom, in his own right. You can't compare. You just have to be yourself. And once he understands that, it'll be that much easier for him to get to the next level."

Syndergaard has found motivation this spring in the way his 2014 season ended — with a phone call in a Reno hotel room. While brushing his teeth, he had missed a phone call from general manager Sandy Alderson. Before dialing, he had assumed it was the one that would bring him to New York.

Instead, Alderson told Syndergaard his season was over. The message was "heart-breaking," he says.

It is a phone call he hopes to avoid. In his mind, the only way this season finishes successfully is if it is with the Mets.

"Being in the big leagues has been my dream ever since I was a little kid," Syndergaard said. "Having someone tell you that...I don't want to hear that phone call again. I'd rather have a more positive connotation to it."